This invention concerns a locking cap with a snap hinge with a hinge strap attaching to a free-standing crosspiece on at least one side of the locking cap.
A locking cap of this type is known from German patent application DE-OS 31 50 493 in which the locking cover is not only connected by a middle hinge but also by hinge straps located on both sides of it. The latter form reversible energy accumulators (potential energy storing members) in their direction of action which stress the locking cover after going beyond a dead centre position into the extreme positions, i.e. closing, opening.
With such one-piece extruded locking caps, so-called white fracture results from overstretching of the participating material sections. This is perceived as at least visually disturbing, above all for attractive containers. Depending on the dyeing of the plastic material, there is a glaring colour contrast.